Centrifugal machine

ABSTRACT

A centrifugal machine, such as a centrifugal pump, has a support and a propeller shaft which is rotatably mounted on the support. A plurality of propeller vanes are mounted on the propeller shaft for rotation with the same and can be moved between at least two inclined positions relative to the axis of the propeller shaft. An arrangement is provided for moving the vanes between their positions, and a drive is provided for activating this arrangement. The drive includes a drive shaft coaxial with the propeller shaft and rotatable relative to the same, being connected to the adjusting arrangement. A rotor of an electromotor is mounted on the drive shaft for rotation with the same and a stator surrounds the rotor and is mounted on the support. A sleeve is mounted on an end portion of the propeller shaft for rotation with the same, and this sleeve is interposed between and out of contact with the stator and the rotor and fluid-tightly surrounds the latter.

United States Patent Eckes et al.

[ CENTRIFUGAL MACHINE [75] Inventors: HeinzEckes, Bremen, Germany;

Klein Schanzlin & Becker Aktiengesellschalt, 03, Frauenthal/Pfalz [73]Assignee: Klein, Schanzlin & Becker Aktiengesellschaft,Frauenthal/Pfalz, Germany [22] Filed: Oct. 5, 1973 [21] Appl. No.:403,878

[30] Foreign Application Priority Data Octv 14, 1972 Germany 2250473[52] -U.S. Cl. 415/130, 416/155 [51] Int. Cl. F04d 29/36, B63h 1/06 [58]Field of Search 416/155, 156; 415/129, 415/130, 140, 141

[5 6] References Cited UNITED STATES PATENTS 1,181,458 5/1916 lskols..4l6/l55 1,374,786 4/1921 Walker 416/155 1,947,653 2/1934 Moody 4l6/l552,327,274 8/1943 Lerine 416/155 2,595,231 5/1952 Dermond.. 416/1552,860,535 Horrell 416/155 FOREIGN PATENTS OR APPLICATIONS PrimaryExaminer-Henry F. Raduazo Attorney, Agent, or Firm-Michael S. Striker [57] ABSTRACT A centrifugal machine, such as a centrifugal pump, has asupport and a propeller shaft which is rotatably mounted on the support.A plurality of propeller vanes are mounted on the propeller shaft forrotation with the same and can be moved between at least two inclinedpositions relative to the axis of the propeller shaft. An arrangement isprovided for moving the vanes between their positions, and a drive isprovided for activating this arrangement. The drive includes a driveshaft coaxial with the propeller shaft and rotatable relative to thesame, being connected to the adjusting arrangement. A rotor of anelectromotor is mounted on the drive shaft for rotation with the sameand a stator surrounds the rotor and is mounted on the supportJA sleeveis mounted on an end portion of the propeller shaft for rotation withthe same, and this sleeve is interposed between and out of contact withlatter.

5 Claims, 1 Drawing Figure 5/1958 Germany 415/130 CENTRIFUGAL MACHINEBACKGROUND OF THE INVENTION:

The present invention relates generally to a centrifugal machine, andmore particularly to a centrifugal machine constructed as a centrifugalpump of vertical type.

It is already known to construct apparatus of this type, and inparticular to provide an arrangement for varying the inclination of thepropeller vanes with reference to the axis of the propeller shaft onwhich they are mounted. Such construction is, for instance, disclosed inGerman allowed application Pat. No. 2,015,112, to which reference may behad for details of the construction and operation. It is also known toelectrically perform this adjustment of the vanes with reference to theaxis of the propeller shaft, for instance from German allowedapplication Pat. No. 1,528,841 to which reference may also be had forfurther details.

This type of apparatus has the advantage that the entire arrangement foradjusting the inclination of the vanes is located close to the latter,and requires only a small amount of space. It eliminates further the useof a special coupling with a built-in motor for carrying out theadjustment of the vanes, and with a gear drive, which were heretoforerequired and had to be separately installed. Also, the use of longmechanical connecting elements, such as rods or sleeves with thecorresponding couplings, is avoided, and the propeller shaft itself canbe of solid cross-section rather than hollow as was necessary in theprevious constructions.

There is, however, still one aspect in which the otherwise satisfactoryprior-art approach should be further improved. This is the fact that theprovision of the electromotor for adjusting the inclination of the vanesincreases the axial length of the centrifugal machine, as compared tothe length of the same machine which is not provided with such anadjusting arrangement. This means that the propeller shaft and thecasting for the hub must be different in both instances, that is it isimpossible to use identical components in both cases. Evidently, this isundesirable in terms of manufacturing economy and stock-keepingrequirements. Also, it is necessary to provide slip rings and brushes oranalogous components to supply electric energy to the motor foradjusting the inclination of the. vanes, and of course the electricalcomponents must be insulated with respect to the medium which is beingpumped and provision must be made for protecting them against excessivewear.

SUMMARY OF THE INVENTION Accordingly, it is a general object of thepresent invention to provide the aforementioned further improvements.

More particularly, it is an object of the present inven tion to providean improved centrifugal machine, particularly an upright centrifugalpump, which incorporates these improvements.

In keeping with the above objects, and others which will become apparenthereafter, one feature of the invention resides, in a machine of thecharacter which is described herein, in a combination comprising asupport and a propeller shaft rotatably mounted on the support andhaving an end portion. A plurality of propeller vanes is mounted on thepropeller shaft for rotation with the same and also for movement betweenat least two inclined positions relative to an axis of the propellershaft. Moving means is provided for effecting the movement of the vanesbetween their positions, and drive means is provided for driving themoving means. The drive means includes a drive shaft coaxial with thepropeller shaft and rotatable relative to the same. The drive shaft isconnected to the moving means. A rotor is mounted on the drive shaft forrotation with the same, and a stator surrounds the rotor and is mountedon the support A sleeve is mounted on the end portion.

of the propeller shaft for rotation with the same, and is interposedbetween and out of contact with the stator onto the rotor, the latter ofwhich it surrounds in fluidtight relationship.

Utilizing the construction according to the present invention, it is nowpossible to use the casting for the hub and the propeller shaft both ina centrifugal pump which is not provided with an arrangement foradjusting the inclination of the vanes, and in a pump which has such anarrangement. In otherv words, because the arrangement according to thepresent invention does not increase the dimensions of the pump, theaforementioned components can be of one andthe same size for both typesof pumps. I

Moreover, the construction according to the present invention omits thenecessity for supplying electrical energy to the electromotor by meansof slip rings, and thus avoids the disadvantages attendant thereto. Theprovision of the sleeve, which does not participate in any. movementsduring changingof the inclination of the vanes, reliably precludes anyaccess of medium being pumped to the components which are to beprotected. Moreover, if the medium is of the type which contains solidparticles, for instance sand contained in sea water or the like, thendamage to the various components of the drive means due to contact withsuch particles is reliably avoided by the presenceof the sleeve. Suchdamage might result in a blocking and destruction of the drive if thesleeve were not arranged in the manner disclosed herein.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The single FIGURE is a fragmentaryvertical section through a centrifugal pump embodying the invention.

DESCRIPTION OF THE PREFERRED- EMBODIMENTS The embodiment illustrated inthe FIGURE shows the invention on hand of a centrifugal pump of theaxial type, having a vertical propeller shaft. The pump has a suctionnozzle 1 which is provided with a cross-shaped member 2 serving as aguide and flow rectifier for the incoming liquid being pumped. Themember 2 has a hollow hub 3 which constitutes a support on which thestator 4 of an electromotor is mounted. Electrical energy is suppliedfrom the exterior via a cable 5 through a hollow rib of the member 2.

A thin-walled hollow cylinder or sleeve 7 is provided on the propellerhub 6, with which it is concentric and to which it is fluid-tightlysecured. The sleeve 7 rotates with the hub 6 and is located between butout of contact with the stator 4 and the cage rotor 8, which latter islocated within the confines of the stator 4. The rotor 8 is mountedon anelongated drive shaft 9 of a coaxial step-down gear 10 which is alsomounted in the hub 3, and the shaft portion 11 of which is configuratedas a screw having self-locking threads which cooperate with the internalthreads of a spindle nut 13 which is fixedly mounted in a cross-mount14. The latter is movable only axially of the shaft 11, in dependenceupon the turning of the latter and in dependence upon the inclinationwhich it is to impart to the axis 15 of the propeller vanes with respectto the longitudinal axis of rotation 16 of the propeller shaft. Aconnection between the cross-mount 14 and the propeller vanes 21 can becarried out by means of the double-pivoted lug 17 which can pivot aboutthe pivot points 17a and 17b, or by other means. Thus, when the shaft 11isturned by the electromotor, the crossmount 14 is moved via the nut 13and changes the inclination of the axes 15 of the respective vanes 21with respect to the axis of rotation 16.

Rotation of the cross-mount 14', which is supposed to move only axially,is prevented in suitable manner. ln the illustrated embodiment, a roller22 is provided on the cross-mount 14 and engages in an axially extendingguide recess 23. Of course, two or more such rollers or analogouscomponents can be provided, and each can be arranged to cooperate withits own guide recess 23.

The large axial forces and the small radial forces which act in the pumpare taken up by a double-acting bearing 24, preferably a roller bearing.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in acentrifugal machine, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can I characteristics of the genericor specific aspects of this invention and, therefore, such adaptationsshould and are intended to be comprehended within the meaning and rangeof equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. in a machine of the character described, a combination comprising asupport; a propeller shaft rotatably mountedon said support and havingan end portion; a plurality of propeller vanes mounted on said propellershaft for rotation therewith and for movement between at least twoinclined positions relative to an axis'of said propeller shaft; movingmeans for effecting movement of said vanes between said positions; anddrive means for said moving means, including a drive shaft coaxial withsaid propeller shaft and rotatable relative to the same and connected tosaid moving means, a electric rotor mounted on said drive shaft forrotation therewith, 'a electric stator surrounding said rotor andmounted on said support, and a sleeve mounted on said end portion ofsaid propeller shaft for rotation with the same, said sleeve beinginterposed betweenand out of contact with said stator and rotor andfluid-tightly surrounding the latter.

2. A- combination as defined in claim 1; further comprising a spokedflow-guiding element having a hollow hub, and wherein said'sleeve, rotorand stator are at least partially located withinthe confines of saidhub.

3. A combination as defined in claim 2, wherein said support forms asuction nozzle, and said element-is located in said nozzle.

'4. Acombination as defined in claim 1, wherein said propeller shaftincludes a casing mounted on and rotatable with said end portion andhaving an opening coaxial with said axis; said drive shaft extendingthrough said opening and having one portion located within and anotherportion locatedwithout said casing, and said rotor being mounted on saidother portion.

5. A combination as defined in claim 4, wherein said sleeve is coaxialwith said opening exteriorly of said casing, said sleeve having an openend in registry with said opening and sealingly connected with saidcasing,

anda closed end remote from said open end.

1. In a machine of the character described, a combination comprising a support; a propeller shaft rotatably mounted on said support and having an end portion; a plurality of propeller vanes mounted on said propeller shaft for rotation therewith and for movement between at least two inclined positions relative to an axis of said propeller shaft; moving means for effecting movement of said vanes between said positions; and drive means for said moving means, including a drive shaft coaxial with said propeller shaft and rotatable relative to the same and connected to said moving means, a electric rotor mounted on said drive shaft for rotation therewith, a electric stator surrounding said rotor and mounted on said support, and a sleeve mounted on said end portion of said propeller shaft for rotation with the same, said sleeve being interposed between and out of contact with said staTor and rotor and fluid-tightly surrounding the latter.
 2. A combination as defined in claim 1; further comprising a spoked flow-guiding element having a hollow hub, and wherein said sleeve, rotor and stator are at least partially located within the confines of said hub.
 3. A combination as defined in claim 2, wherein said support forms a suction nozzle, and said element is located in said nozzle.
 4. A combination as defined in claim 1, wherein said propeller shaft includes a casing mounted on and rotatable with said end portion and having an opening coaxial with said axis; said drive shaft extending through said opening and having one portion located within and another portion located without said casing, and said rotor being mounted on said other portion.
 5. A combination as defined in claim 4, wherein said sleeve is coaxial with said opening exteriorly of said casing, said sleeve having an open end in registry with said opening and sealingly connected with said casing, and a closed end remote from said open end. 